Study On Protection Priority Areas Of Vascular Plants In Guangxi

With the disturbance of human activities,the rate of species extinction has increased,and the protection of biodiversity is imminent.It is the key to protect biodiversity by identifying priority areas to achieve maximum biodiversity protection with minimum cost.Guangxi is rich in biodiversity,which is an important constituent of biodiversity of China and even the whole world.Therefore,it is of great significance to study the biodiversity and conservation priority areas in Guangxi.In this study,111 county-level administrative regions in Guangxi were taken as the basic units,and the data were collected according to records from literatures and specimens,analyzes the family and genus compositions of vascular plants,endangered species and endemic species in Guangxi,and analyzes the species richness,threatened species richness,endemic species richness and phylogenetic diversity pattern of vascular plants in Guangxi.Then,through principal component analysis,the above four diversity indexes were synthesized into a protection index,and the protection priority areas were identified by using the protection index.Finally,the protection efficiencies of the existing nature reserves were evaluated by comparing the selected protection priority areas with the existing nature reserves.The main conclusions are as follows:(1)Guangxi is rich in vascular plants,including 8 609 species belonging to 1 865 genera in 269 families,among which the top 10 families are Orchidaceae,Fabaceae,Gesneriaceae,Poaceae,Rubiaceae,Asteraceae,Lauraceae,Labiatae,Urticaceae and Rosaceae;The top 10 genera are Elatostema,Primulina,Begonia,Ilex,Rhododendron,Aspidistra,Carex,Rubus,Ficus and Camellia.There are 173 families,619 genera and 1814 threatened species in Guangxi,among which Orchidaceae has the most threatened species at family level,followed by Gesneriaceae.Primulina is the highest at genus level.Endemic species include 984 species from 321 genera in 108 families,among which Gesneriaceae has the largest number of family level species,and Primulina has the largest number of genus level species.(2)The species richness of vascular plants in Guangxi has a high correlation with phylogenetic diversity,and they are all concentrated in Northeast Guangxi(Jiuwandashan Mountain,Maoershan Mountain and other Nanling Mountains),mountainous areas of Northwest Guangxi(Cenwanglaoshan Mountain,Jinzhongshan Mountain and Fenghuangshan Mountain),karst mountainous areas of West Guangxi,mountainous areas of Southwest Guangxi(Daqingshan Mountain and Shiwandashan Mountain)and mountainous areas of Middle Guangxi(Damingshan Mountain and Dayaoshan Mountain).Different from the pattern of species richness and phylogenetic diversity,the pattern of threatened species richness and endemic species richness are concentrated in karst mountain areas in Western Guangxi and mountainous areas in Southwestern Guangxi(Daqingshan Mountain and Shiwandashan Mountain).(3)According to the protection index,15 county-level protection priority areas are selected,namely Longzhou County,Napo County,Jingxi City,Rongshui Miao Autonomous County,Longsheng Multinational Autonomous County,Shangsi County,Jinxiu Yao Autonomous County,Xing,an County,Huanjiang Maonan Autonomous County,Lingui District,Wuming District,lingyun County,Fangcheng District,Ziyuan County and Quanzhou county.These 15 county-level administrative areas are mainly distributed in the mountainous areas of Northeast Guangxi(Jiuwandashan Mountain,Maoershan Mountain),karst mountainous areas of West Guangxi,mountainous areas of Southwest Guangxi(Daqingshan Mountain and Shiwandashan Mountain)and mountainous areas of Middle Guangxi(Damingshan Mountain and Dayaoshan Mountain).(4)There is a high spatial correspondence between 15 county-level conservation priority areas and existing 30 nature reserves.However,compared with the selected protection priority areas,the existing nature reserves have some limitations,such as small area,low protection level,vacant protection and low protection efficiency.Based on this,this study suggests that the existing nature reserves in Northeast and Southwest Guangxi are better to be merged to establish Nanling National Park in Northeast Guangxi and Karst National Park in Southwest Guangxi.In conclusion,it is proposed that merging phylogenetic diversity into conservation index and using quantifiable and more objective protection index provides a new way for the study of biodiversity conservation priority areas.